BIOM20002 Lecture Notes - Lecture 52: Pressure Gradient, Alveolar Pressure, Thoracic Wall
Document Summary
Need much ventilation to sustain high metabolism (since warm blooded) External respiration: ventilation or breathing: exchange of air between atmosphere & lungs, exchange of o2 & co2 between lungs & blood, transport of o2 & co2 by blood, exchange of o2 & co2 between blood & cells. Intracellular reaction of o2 with nutrients to produce co2, water & energy. Aids in regulation of blood ph by altering amount of h+-generating co2 exhaled. ph regulates ventilation. Supplies oxygen for acceptance of electrons in electron transport chain of mt. Provides additional route for water loss & heat elimination (although not effective in humans). Other mammals can use it for panting (heat regulation) Under normal atmospheric conditions, co2 levels most directly controls breathing. What keeps the lungs inflated: pleural sac which attaches the lung to the thoracic wall, pressure difference between the atmosphere, lungs and pleural sac. Outer layer attached to rib cage, other attached to lungs.
